1. Field of the Invention
The present invention relates to scheduling in playback order for efficient reading of data from, for example, a recording medium such as an optical disk.
2. Description of the Related Art
In recent years, optical disks and other types of recording media which have very high recording rates and reading rates have come into practical use, and it has become possible to record long-time video data with relatively high picture quality.
Even if the recording rate and reading rate of a recording medium are high, when a stream of the video data is recorded discontinuously, that is, in a form in which the stream is divided into pieces, seeking occurs in the discontinuous portions. In a case in which the seeking causes reading of the video data to be late for the time the video data must be played back, playback of the video data is interrupted.
For example, Japanese Unexamined Patent Application Publication No. 10-50037 discloses a method in which, in addition to a material data disk unit for playing back material data, a working disk unit is used. By copying, to the working disk unit, data in the vicinity of an editing point in the material data, and selectively using outputs from the material disk unit and the working disk unit, as required, playback of the material data is prevented from being interrupted due to seeking occurring at the editing point.
In the method in Japanese Unexamined Patent Application Publication No. 10-50037, in order to prevent the playback from being interrupted, the working disk unit must be used in addition to the material data disk unit, and it is required that both disk units be controlled so that their outputs are selectively used, as required.
Also, it is preferable that reading of data from a recording medium such as an optical disk can be efficiently performed.